El profesor Hardwigg, su sobrino Harry, y su guía Han exploran un cráter volcánico en Islandia que los dirige al centro de la Tierra. Professor Hardwigg, his nephew Harry, and their guide Hans explore a volcanic crater in Iceland that leads them to the center of the Earth.

This book, constructed on one continuous folded page, explores the layers of the Earth from human-made structures like sewers, subways and archeological finds, down through various formations of rock, to the Earth's core and back up again.